This invention relates to the field of guide-wires for advancing intraluminal devices such as stent delivery catheters, balloon dilatation catheters, atherectomy catheters and the like within body lumens.
In a typical percutaneous coronary procedure, a guiding catheter having a pre-formed distal tip is percutaneously introduced into a patient""s peripheral artery, e.g. femoral or brachial artery, by means of a conventional Seldinger technique and advanced therein until the distal tip of the guiding catheter is seated in the ostium of a desired coronary artery. A guide-wire is first advanced by itself through the guiding catheter until the distal tip of the guide-wire extends beyond the arterial location where the procedure is to be performed. A rapid exchange type catheter, such as described in U.S. Pat. No. 5,061,273 (Yock) is mounted onto the proximal portion of the guide-wire which extends out of the proximal end of the guiding catheter which is outside of the patient. The rapid exchange type catheter is advanced over the guide-wire, while the position of the guide-wire is fixed, until the operative means on the rapid exchange type catheter is disposed within the arterial location where the procedure is to be performed. After the procedure the intra-vascular device may be withdrawn from the patient over the guide-wire or the guide-wire repositioned within the coronary anatomy for an additional procedure.
Conventional guide-wires for angioplasty, stent delivery, atherectomy and other intra-vascular procedures usually comprise an elongate core member with one or more tapered segments near the distal end thereof. A shapeable segment of the core member or a shapeable ribbon which is typically secured to the distal extremity of the core member may be utilized to guide the guidewire into desirable arterial branches. A flexible body member, such as a helical coil or a tubular body of polymeric material, is typically disposed about the distal portion of the core member and/or shapeable segment. The leading tip is highly flexible and will not damage or perforate the vessel and the portion behind the distal tip is increasingly stiff which better supports a balloon catheter or similar device which is to be advanced over the guidewire.
Further details of guide-wires, and devices associated therewith for various intervention procedures can be found in U.S. Pat. No. 4,748,986 (Morrison et al.); U.S. Pat. No. 4,538,622 (Samson et al.); U.S. Pat. No. 5,135,503 (Abrams); U.S. Pat. No. 5,341,818 (Abrams et al.); and U.S. Pat. No. 5,345,945 (Hodgson, et al.) which are hereby incorporated herein in their entirety by reference thereto.
During the course of a procedure, several guidewires may be used, and the differences in design of various guidewires are subtle and can be difficult to ascertain by visual inspection, once a guide-wire has been removed from its supplier packaging. For example, it is difficult to easily discriminate between a 0.014xe2x80x3 HTF(Hi Torque Floppy)II guide-wire and a 0.014xe2x80x3 HTFII Extra Support guide-wire, both of which are manufactured by the present assignee, Advanced Cardiovascular Systems, Inc. These devices are very similar in appearance and the distinctions are not readily seen by the user once they are removed from their packages.
The difficulty in visual identification of guide-wires can lead to a problem of inadvertent mixing and erroneous substitution of guide-wires during the course of a procedure. The size and shape of typical guide-wires do not provide surface area for conventional equipment label plates, such as would typically bear a maker""s model identifier, part number, and the like. What has been needed is a system to permit guide-wires to be accurately and quickly identified by surgical personnel during preparation and performance of an intra-vascular procedure.
The present invention is directed to a system and method of encoded markings for medical devices such as elongated intracorporeal devices, particularly devices such as guide-wires or other intra-vascular or surgical devices which do not have sufficient surface area for conventional marking systems. The marking system provides coded markings on the exterior of the intracorporeal device, preferably on the proximal segment, base or handle portion of the device.
The markings include coded indicators of device characteristics, such as identifying data, qualitative data and/or quantitative data, e.g., the design family, the dimensions, and other pertinent specifications. The coded markings may be repeated on the packaging in which the guide-wire is supplied, together with additional correlated identifying information and specifications. Preferably, a visual display or reference aid setting forth the data/code correlation is also included for placement in the use environment to assist the user in the interpretation of the coded markings, such as a reference chart card mounted on a wall or other convenient surface. The reference aid may also be a computer database, optionally including a search engine to display selected data.
The marking system embodying features of the invention is particularly useful for guide-wire properties which are not externally observable (e.g., type of shaping ribbon encased in flexible body), or for quantitative differences which are only ambiguously directly observable (e.g., small differences in diameter) particularly during the procedure when portions of the device may be within the patient.
The markings of the invention comprise a series of marking elements applied or fixed to the surface of the device such as a guide-wire preferably at a location which will be readily observable during the procedure such as the proximal segment of the guidewire which extends out of the patient during the procedure. The marking elements comprise a plurality of non-overlapping shaped regions or labels on the device surface. Each marking element corresponds to an information or data category. For example, the data categories for a guidewire might be the guidewire type or family, the size, distal tip construction and the like.
The marking elements are arranged upon the device surface in a pre-determined pattern whereby the spatial location or order of each marking element is representative of the corresponding category, i.e., the spatial pattern of the elements is correlated to the sequential order of the categories. For example, the marking elements may be in a linear array, with the sequence of the elements in the array corresponding to the category order. Note that the category order may be arbitrary, the purpose being to establish a one-to-one correspondence between the data category identity and the marking element identity, the correspondence being determinable by the device user upon inspecting the marked device.
Each such shaped marking element region, in turn, has a code property. The code property is expressed (e.g., by being printed, painted, applied, embossed, displayed, and the like) within the shaped marking element region in any selected one of a range of code property xe2x80x9cvaluesxe2x80x9d, each value of the code property corresponding to a particular data xe2x80x9cvaluexe2x80x9d within the category of the marking element. The code property value may then be inspected or xe2x80x9creadxe2x80x9d by the device user to obtain information or data pertinent to the guide-wire or other device. Note that the term xe2x80x9cvaluexe2x80x9d as used herein may refer to various types of data or characteristics, both quantitative and qualitative.
Each data category includes a plurality of data elements relating to the category, each data element being one value of a range of values relevant to device class. The data elements may be model data identifiers, qualitative data values and/or quantitative data values pertaining to a range of different specimens (e.g., a range of models, a range of design types identifiers, a range of dimensional values, and the like). Within each category, each data element is associated or correlated with a specific, distinct code property value.
Thus, each such mark is coded to convey a single data element, i.e., each mark displays a value of the code property which corresponds to and represents the expressed data element value. Each mark may convey an independent data element via its code property (e.g., a, single code element to specify design type). Alternatively, two or more adjacent marks may be xe2x80x9creadxe2x80x9d in combination so that their combined data elements conveys an integrated item of information (e.g., multiple digits read together as a single numerical value).
In one marking system embodiment, the marks comprise a plurality of bands about the circumference of the guide-wire proximal segment, shaped as rings of sufficient width to be clearly visible upon user inspection. The bands or rings are disposed in a linear array along the longitudinal axis of the proximal segment, preferably with spacing so that each ring is seen by the user distinct from adjacent rings. Each ring represents a data or information category with respect to the guide-wire or device (e.g., design type, diameter and the like)
A preferred code property is color, and thus each marking element region has a selected color (xe2x80x9ccolor valuexe2x80x9d). The term xe2x80x9ccolorxe2x80x9d is used herein broadly to mean a visually distinct color expression, whether due to a distinct hue, saturation level, and the like or combinations thereof. In the example of band or ring-shaped marking elements, on each band the selected color is printed, painted, applied or displayed. The colors are preferably selected so as to be highly visible and distinct under low light levels.
For example, for a category xe2x80x9cguide-wire design typexe2x80x9d, the data elements may be a range of different guide-wire design type designations or xe2x80x9cvaluesxe2x80x9d, each such design type value being associated with a corresponding color or value. For the category xe2x80x9cdiameterxe2x80x9d, the data elements may be a range of different diameter values, with each such value being associated with a distinct color. Thus, for the marking elements placed upon any particular guide-wire or device specimen, for each category the particular color is selected that is associated with the true or correct data element value for the particular specimen.
Note, however, that the same color may be assigned to more than one data element, if the data elements are in different categories. For example, in the case of numerical data, it is convenient for the user if the same color is assigned to the same digital values in each category expressing numerical data.
Alternatively or in addition to color coding, other code properties may be employed in the marking elements, such as distinctive visual patterns within the shaped region, distinctive tactile textures, and the like. If desired, shape of the marking element may itself be a code property. It is preferred that a single code property be employed for all marking elements, although alternatively, different code properties may be used for different categories/marking elements.
Alternatively or additionally, the marking elements may be shapes other than bands about the circumference of the proximal segment. For example, marking element shapes may be shaped as partial circumference bands, circles, ellipses or hexagons, and the like, or combinations of different shapes in the array.
The shape, geometry and/or size of each marking element may be the same, or may be different. For user mnemonic convenience, different categories of data may be conveyed to the user by marking element of a shape which is correlated with the category. For example, the design type of the guide-wire may be conveyed by a wider band, while the diameter may be conveyed by one or more relatively narrow bands. Thus, while the order of a particular marking element in the spatial sequence along the guide-wire body can itself convey unabiguously the particular category of the marking element (e.g., first band codes the design type, second and third bands code the diameter), the use of particular shapes to represent particular categories can reinforce this distinction in the user""s mind.
It may be seen that the logical relationship between selected device characteristics and the categories and data elements may be expressed in the form of a correlation table, data array, or equivalent logical association. Each category is linked to a marking element. For each such linked category/marking element pair, a logical array may be established linking each data element value with a corresponding code value. Thus in the previous guide-wire example, in the category of xe2x80x9cdesign typexe2x80x9d, the category is linked to a particular marking element (e.g., the first band). In turn, each of the plurality of specified design types is linked to a selected color code. Similarly, in the category of xe2x80x9cdiameterxe2x80x9d, each specified diameter value is linked to a selected color. The term correlation table is used in this regard to mean the logical association of elements as described, whether or not expressed in written form, computer memory, and the like.